It is difficult for me to make just one choice in the Laurentians, as there are so many interesting trails. Those of Ste-Agathe-Sud, Val-David/Val-Morin, Mont-Roland and Sainte-Lucie-des-Laurentides are all very beautiful, and absolutely worth doing at least once each, every winter.
Located in Morin-Heights, my recommended route is from route 329 (at the bottom of the Bouleaux parking lot). You must first climb the Swiss trail, then turn off onto Lover’s Leap. After Corbeau, go back and forth to the viewpoint at the top of Rapide-Blanc. On the way back, we continue on Rapide-Blanc until the end. At the Viking W crossroads, take this path on the right to return to Route 329, over hill and valley. But be careful, it's not over! You must then cross the river (via the bridge, if the ice is questionable) to go find JRJ, towards the south to reach the intersection of the Auberge trail, which you must take on the right to end up at your starting point. I rate this route at an intermediate level with some challenging sections.
Distance: approximately 15 km